Hermetic Compressor

ABSTRACT

It is disclosed a hermetic compressor, provided with at least one fluid expansion chamber, whose useful volume is narrowly defined between a section of one of the faces (inner or outer) of the airtight housing of the compressor and at least one wall section adjacently attached to one of the faces of the airtight housing of the compressor.

FIELD OF THE INVENTION

The invention in question relates to a hermetic compressor, and, moreparticularly, a hermetic compressor provided with at least one fluidexpansion chamber, that is, a pulsation attenuating chamber that can beused in the discharge line (discharge muffler) or in the suction line(suction muffler).

In accordance with the invention in question, the hermetic compressordisclosed herein is distinguished in that it comprises an airtighthousing and at least an additional wall section, wherein the volumedefined between the airtight housing and the additional wall sectionends up defining said fluid expansion chamber.

BACKGROUND OF THE INVENTION

As is well known to those skilled in the art, hermetic compressors,especially those comprised of positive displacement compressionmechanisms, include, among other components, discharge expansionchambers (also referred to as “discharge mufflers”) and suctionexpansion chambers (also referred to as “suction muffler”). In generallines, the fluid expansion chambers have the general function ofattenuating the pulsations of the useful fluid, being that thefunctional principles which governs the passive operation of the fluidexpansion chambers are widely known to professionals and theoreticiansin the area of acoustics, besides being particularly detailed inspecialized technical literature.

The current state of the art comprises an infinity of models andconstructions of fluid expansion chambers used in hermetic compressors.

There are, for example, constructions in which the volume of thedischarge expansion chamber is defined by a hollow modular bodyarranged, in a non-anchored manner, within the airtight housing of thehermetic compressor. The fluid communication between the compressionmechanism head, the hollow modular body and the discharge duct isperformed by a rigid metal tubing.

There are, for example, constructions in which the volume of thedischarge expansion chamber is integrally or partially defined in thecompressor block itself. The fluid communication, between thecompression mechanism head, the compressor block and the discharge duct,is performed by a rigid metal tubing.

There are, for example, as described in the patent document U.S. Pat.No. 4,782,858, constructions in which the volume of the dischargeexpansion chamber is integrally defined in the cap of the compressionmechanism head. The fluid communication between the compressionmechanism head and the discharge duct is performed by a rigid metaltubing.

There are, for example, as described in the patent document US2009/162215, constructions in which the volume of the dischargeexpansion chamber is segmented in two, the first “sub volume” beingdefined integrally in the cap of the head and the second “sub volume”being defined between the cap of the head and the outer face of asegment of the compression cylinder block, the fluid communicationbetween the two “sub-volumes” being defined in the arrangement itself,without the overall structure of the cylinder block being altered. Thefluid communication between the compression mechanism head and thedischarge duct is performed by a rigid metal tubing.

It is noted, however, that regardless of the model or construction ofthe known expansion chambers, they are always arranged within theairtight housing of the compressor, that is, they are arranged in theinternal environment whose useful volume is shared with the compressionmechanism, such as the electric motor, with the compressor block, amongother components and systems.

In a general manner, the fact that an expansion chamber is arrangedwithin the airtight housing generates at least three drawbacks, one fromthe thermal point of view, the other from the dimensional point of view,and the third relating to aspects of reliability.

With regard to the thermal point of view, it is noted that the dischargeexpansion chamber is arranged in an environment (within the airtighthousing), whose temperature is lower than the temperature of thedischarge fluid, that is, the temperature outside the dischargeexpansion chamber is less than its within temperature. Consequently, theinternal environment of the housing of the compressor (suction fluid)suffers severe thermal exchange, after all, its temperature ispejoratively influenced by the temperature of the circulating dischargefluid through the discharge expansion chamber. As a consequence, thereis an increase in the suction temperature of the compressor and, in thisway, reducing the volumetric efficiency and, hence, the energyefficiency thereof.

As far as the dimensional point of view is concerned, it is noted thatthe discharge expansion chamber occupies a useful volume which couldotherwise be suppressed in order to enable the miniaturization of thehermetic compressor housing, which currently is unlikely. Anotherbenefit of reducing internal compressor volume is related to theapplication of high pressure useful refrigerants, such as CO₂, as wellas flammable, wherein the compressors fall into the category of pressurevessel safety, and the internal volume defines the criticality of thedamage. Thus, compressors with smaller internal volumes are advantageousfor this type of application.

With regard to the reliability, it is noted that the reduction of themasses mounted in the discharge tube, which has a relative movementbetween the housing and the internal assembly of the compressor,especially the compressor block, when transporting the compressor, andalso in the moments of on and off of the compressor. The elimination ofthese masses reduces the loads on the pipes, as well as avoids shocks ofthese volumes with the internal components and the housing of thecompressor.

It is, therefore, based on the above-described scenario that theinvention in question arises.

GOALS OF THE INVENTION

Thus, it is the primary goal of the invention in question to disclose ahermetic compressor, provided with at least one fluid expansion chamber,whose useful volume is narrowly defined between a section of one of thefaces (inner or outer) of the airtight housing of the compressor and atleast one wall section adjacently attached to one of the faces of theairtight housing of the compressor.

Accordingly, it is also a goal of the invention in question to provide afluid expansion chamber less susceptible to thermal exchanges and whichoccupies less or no useful space within the airtight housing of thehermetic compressor.

It is also a goal of the invention in question that the fluid expansionchamber of the hermetic compressor now treated be less susceptible toproblems and failures of transport and application of the compressor atthe times of turning the compressor on and off.

Thus, it is one of the goals of the invention in question that thegeneral concept of a fluid expansion chamber, whose useful volume isnarrowly defined between a section of one of the faces (inner or outer)of the airtight housing of the compressor and at least a wall sectionadjacently attached to one of the faces of the airtight housing of thecompressor can be used both as a discharge muffler and a suctionmuffler.

BRIEF DESCRIPTION OF THE INVENTION

The goals summarized above are fully achieved by the hermetic compressordisclosed herein, which comprises an airtight housing, at least onereciprocating compression mechanism arranged within the airtight housingand at least one fluid expansion chamber. Said fluid expansion chamberis formed between one of the faces of the airtight housing and the innerface of a first modular body, hermetically attached to one of the facesof the airtight housing and comprises at least one inlet path and atleast one outlet path.

In accordance with the invention in question, the fluid expansionchamber may comprise a discharge fluid expansion chamber (dischargemuffler) or a suction fluid expansion chamber (suction muffler).

Also in accordance with the invention in question, the fluid expansionchamber may be external (formed between the outer face of the airtighthousing and the inner face of a first modular body hermetically attachedto the outer face of the airtight housing) and/or internal (formedbetween the inner face of the airtight housing and the inner face of afirst modular body hermetically attached to the inner face of theairtight housing).

Further, still in accordance with the invention in question, the inletpath and the outlet path of the fluid expansion chamber can be fluidlyaligned or misaligned.

Optionally, the hermetic compressor disclosed herein further comprisesat least one second fluid expansion chamber fluidly connected, inseries, to the “main” fluid expansion chamber.

In one of the possible embodiments of such optional embodiment, thesecond fluid expansion chamber is internal, being arranged within theairtight housing and may be formed, at least partially, between theinner face of the airtight housing and the inner face of a secondmodular body or be formed, at least partially, between the outer face ofthe first modular body and the inner face of a second modular body.

In another of the possible embodiments of such optional embodiment, thesecond fluid expansion chamber is external, being arranged on theexterior of the airtight housing and may be formed, at least partially,between the outer face of the airtight housing and the inner face of asecond modular body or be formed, at least partially, between the outerface of the first modular body and the inner face of a second modularbody.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention in question will be particularly detailed on the basis ofthe illustrative Figures listed below, which:

FIGS. 1A and 1B illustrate, in a schematic form, the most basic andsimplified embodiments of the invention in question;

FIGS. 2A, 2B, 2C and 2D illustrate, in a schematic form, possibleembodiments of the optional embodiment of the invention in question; and

FIG. 3 illustrates, in a schematic form, another possible embodiment ofthe optional embodiment of the invention in question.

DETAILED DESCRIPTION OF THE INVENTION

In accordance with the central goals of the invention in question, it isdesired to “shift” the volume of a traditional fluid expansion chamber(discharge or suction), normally displaced within the airtight housingof a hermetic compressor, to the vicinity of said airtight housing, sothat such volume becomes an integral part of the housing of thecompressor.

Of course, such invention has the potential to optimize the internalvolume of the compressor, in addition to reducing the emission of heatwithin the housing, promoting greater energy efficiency. In addition,such invention simplifies the overall manufacturing process of thecompressor, after all, traditional brazing processes are replaced byfaster and less expensive welding processes.

In a general manner, the hermetic compressor treated herein is atraditional hermetic compressor, and, of course, certain details notrelevant for the understanding of the invention in question have beenomitted and/or deleted. It is again emphasized that omission or deletionof these details (components that integrate the compression or thedamping mechanisms, for example) does not prejudice the fullunderstanding of the invention in question.

The invention in question, in its inventive core, is illustrated inFIGS. 1A and 1B.

As illustrated in these Figures, the hermetic compressor disclosedherein comprises an airtight housing and a fluid expansion chamber,being that the great inventive merit of the invention in questionconsists in the fact that said fluid expansion chamber—rather than beingdetached and conformed in itself, as it happens in the current state ofthe art—is formed between one of the faces of the airtight housing andthe inner face of a first modular body hermetically attached to one ofthe faces of the airtight housing.

Specifically, as illustrated in FIG. 1A, said fluid expansion chamber(2) is external to the airtight housing (1), being formed between theouter face (12) of the airtight housing (1) and the inner face (31) ofthe first modular body (3), which is, in turn, hermetically attached tothe same outer face (12) of the airtight housing (1). It is furthernoted that, such as illustrated, said fluid expansion chamber (2) is adischarge fluid expansion chamber.

Specifically, as illustrated in FIG. 1B, said fluid expansion chamber(2) is internal to the airtight housing (1), being formed between theinner face (11) of the airtight housing (1) and the inner face (31) ofthe first modular body (3), which is, in turn, hermetically attached tothe same inner face (11) of the airtight housing (1). It is furthernoted that, such as illustrated, said fluid expansion chamber (2) is asuction fluid expansion chamber.

In both embodiments illustrated in FIGS. 1A and 1B, it is noted that thefluid expansion chamber (2) comprises at least one inlet path (21) andat least one outlet path (22).

In the embodiment illustrated in FIG. 1A, the inlet path (21) is relatedto a fluidic communication means (tube or mere through-hole, to giveonly two examples) which, bypassing the airtight housing (1), connectsits internal environment to the volume of the fluid expansion chamber(2). The outlet path (22) is related to a fluid communication means(discharge duct tube, to give only one example) able to allow theconnection between the hermetic compressor and the discharge line of anexternal system (not illustrated), such as, for example, a coolingsystem.

In the embodiment illustrated in FIG. 1B, the inlet path (21) is relatedto a fluidic communication means (suction duct tube, to give only oneexample) which, bypassing the airtight housing (1), is able to allow theconnection between the suction line of an external system (notillustrated), such as, for example, a cooling system and the hermeticcompressor. The outlet path (22) is related to a fluidic communicationmeans (tube or mere through-hole, to give only two examples) capable ofconnecting the volume of the fluid expansion chamber (2) to the internalenvironment of the compressor or to the cylinder of the compressionmechanism (not illustrated).

In both embodiments illustrated in FIGS. 1A and 1B, in addition to theremaining embodiments described in the invention in question, the firstmodular body (3) is preferably made of metal alloy and attached to oneof the faces (11 and 12) of the airtight housing (1), preferably bymeans of welding. Nothing prevents the modular body from beingmanufactured with other types of materials, such as polymeric, that thefixing is of alternative forms, such as, for example, glue.

Although the invention in question does not intentionally addressthermal and acoustic issues, it is worth emphasizing that the general,dimensional and structural format of the first modular body (3), as wellas the general features of the fastening medium, must respect thefeatures of acoustics of each project. In this regard, it is mostimportant to note that in any of the embodiments illustrated in FIGS. 1Aand 1B, the inlet path (21) and the outlet path (22) of the fluidexpansion chamber (2) can be arranged in a fluidly aligned manner or ina fluidly misaligned manner.

Optional embodiments of the invention in question, in accordance withthe inventive core described above, are illustrated in FIGS. 2A, 2B, 2Cand 2D.

In all these optional embodiments it is noted the existence of saidfluid expansion chamber (2) (internal or external to the airtighthousing (1), formed between one of the faces (11 and 12) of the airtighthousing (1) and the inner face (31) of a first modular body (3)hermetically attached to one of the faces (11 and 12) of the airtighthousing (1)) and the existence of at least one second fluid expansionchamber (4) fluidly connected, in series, to the fluid expansion chamber(2). The fluid expansion chambers (2 and 4) can conform avolume-in-series for discharge fluid or a volume-in-series for suctionfluid.

In general lines, the formation of the second fluid expansion chamber(4) always has a second modular body (5), which, also in general lines,is substantially analogous to the first modular body (3).

The formatting of the second fluid expansion chamber (4), alwaysemploying the second modular body (5), can be varied, some examplesbeing illustrated in cited FIGS. 2A, 2B, 2C and 2D.

As illustrated in FIG. 2A, the fluid expansion chamber (2) and thesecond fluid expansion chamber (4) are both external and, preferably,dedicated to the discharge fluid. In this embodiment, the second fluidexpansion chamber (4) is formed only between the outer face (32) of thefirst modular body (3) and the inner face (51) of a second modular body(5).

As illustrated in FIG. 2B, the fluid expansion chamber (2) and thesecond fluid expansion chamber (4) are both internal and, preferably,dedicated to the suction fluid. In this embodiment, the second fluidexpansion chamber (4) is formed between the outer face (32) of the firstmodular body (3), the inner face (11) of the airtight housing (1) andthe inner face (51) of a second modular body (5).

As illustrated in FIG. 2C, the fluid expansion chamber (2) and thesecond fluid expansion chamber (4) are both external and, preferably,dedicated to the discharge fluid. In this embodiment, the second fluidexpansion chamber (4) is formed between the outer face (32) of the firstmodular body (3), the outer face (12) of the airtight housing (1) andthe inner face (51) of a second modular body (5).

As illustrated in FIG. 2D, the fluid expansion chamber (2) and thesecond fluid expansion chamber (4) are both internal and, preferably,dedicated to the suction fluid. In this embodiment, the second fluidexpansion chamber (4) is formed only between the inner face (11) of theairtight housing (1) and the inner face (51) of a second modular body(5).

In these four embodiments, it is further noted that the fluid expansionchamber (4) comprises an outlet path (6), which is directed to a fluidiccommunication means (traditional tube, mere through-hole orthrough-tube, to give only three examples). In this sense, it is notedthat the “inlet path” of said fluid expansion chamber (4) always ends upbeing defined by the outlet path (22) of the fluid expansion chamber(2).

The constructive details described (and omitted) with respect to thefluid expansion chamber (2) (possibility of structural and dimensionalvariation, and preferred form of fixation by welding, for example) aresimilarly observed in the fluid expansion chamber (4).

In contrast to the optional embodiments illustrated in FIGS. 2A, 2B, 2Cand 2D, the optional embodiment illustrated in FIG. 3 provides for theuse of two fluid expansion chambers, fluidly connected, in series, oneof these chambers being internally arranged (in relation to the housingof the compressor) and the other of these chambers externally arranged(in relation to the housing of the compressor).

Thus, as arbitrarily defined in FIG. 3, there is provided a hermeticcompressor comprising an airtight housing (1), a first fluid expansionchamber (2) and a second fluid expansion chamber (4), such chambersbeing fluidly connected, in series, defining a volume-in-series fordischarge fluid (it may of course also define a volume-in-series forsuction fluid).

In particular, the first fluid expansion chamber (2) is specially formedonly between the inner face (11) of the airtight housing (1) and theinner face (31) of a first modular body (3) hermetically attached to theinner face (11) of the airtight housing (1), while the second fluidexpansion chamber (4) is specially formed only between the outer face(12) of the airtight housing (1) and the inner face (31) of a firstmodular body (3) hermetically attached to the outer face (12) of theairtight housing (1). The fluid connection between the volumes occurs inan analogous manner to the constructions and options illustrated inFIGS. 2A, 2B, 2C and 2D.

It is important to emphasize that the above description has the solepurpose of describing by way of example the particular embodiment of theutility model in question. Therefore, it is clear that modifications,variations and constructive combinations of the elements performing thesame function, in substantially the same manner, to achieve the sameresults, remaining within the scope of protection delimited by theappended claims.

1. Hermetic compressor, comprising: an airtight housing; at least onereciprocating compression mechanism (not illustrated) arranged withinthe airtight housing; and at least one fluid expansion chamber; saidhermetic compressor being especially characterized in that said fluidexpansion chamber is formed between one of the faces of the airtighthousing and the inner face of a first modular body is hermeticallyattached to one of the faces of the airtight housing; and said fluidexpansion chamber comprises at least one inlet path and at least oneoutlet path.
 2. Hermetic compressor, according to claim 1, characterizedin that the fluid expansion chamber comprises a discharge fluidexpansion chamber.
 3. Hermetic compressor, according to claim 1,characterized in that the fluid expansion chamber comprises a suctionfluid expansion chamber.
 4. Hermetic compressor, according to claim 1,characterized in that the fluid expansion chamber is external, beingformed between the outer face of the airtight housing and the inner faceof a first modular body hermetically attached to the outer face of theairtight housing.
 5. Hermetic compressor, according to claim 1,characterized in that the fluid expansion chamber is internal, beingformed between the inner face of the airtight housing and the inner faceof a first modular body hermetically attached to the inner face of theairtight housing.
 6. Hermetic compressor, according to claim 1,characterized in that the inlet path and the outlet path of the fluidexpansion chamber are fluidly aligned.
 7. Hermetic compressor, accordingto claim 1, characterized in that the inlet path and the outlet path ofthe fluid expansion chamber are fluidly misaligned.
 8. Hermeticcompressor, according to claim 1, characterized in that it furthercomprises at least one second fluid expansion chamber fluidly connected,in series, to the fluid expansion chamber.
 9. Hermetic compressor,according to claim 8, characterized in that said second fluid expansionchamber is internal, being arranged within the airtight housing. 10.Hermetic compressor, according to claim 9, characterized in that saidsecond fluid expansion chamber is formed, at least partially, betweenthe inner face of the airtight housing and the inner face of a secondmodular body.
 11. Hermetic compressor, according to claim 9,characterized in that said second fluid expansion chamber is formed, atleast partially, between the outer face of the first modular body andthe inner face of a second modular body.
 12. Hermetic compressor,according to claim 8, characterized in that said second fluid expansionchamber is external, being arranged on the outside of the airtighthousing.
 13. Hermetic compressor, according to claim 12, characterizedin that said second fluid expansion chamber is formed, at leastpartially, between the outer face of the airtight housing and the innerface of a second modular body.
 14. Hermetic compressor, according toclaim 12, characterized in that said second fluid expansion chamber isformed, at least partially, between the outer face of the first modularbody and the inner face of a second modular body.